Drum drying apparatus



Sept. 22, 1964 H. J. BEHNCKE DRUM DRYING APPARATUS Filed Dec. 1', 1960 2Sheets-Sheet 1 //7 FEM/0k 24 67/75 f/ryen fie/vnc (e Se t. 22, 1964 H.J. BEHNCKE DRUM DRYING APPARATUS 2 Sheets-Sheet 2 Filed Dec. 1, 1960United States Patent 3,149,930 DRUM DRYING APPARATUS Hans J. Behncke,Munich-Putzbrunn, Germany Filed Dec. 1, 1966, Ser. No. 72,931 Claims.(Cl. 34-415) This invention relates to drying apparatus, and moreparticularly to apparatus for drying materials in sheet form, especiallysuch materials as can easily be damaged during drying. The inventionalso relates to a process for drying such sheet material.

Wadding in sheet form, as used to pad clothes and as filler for pillows,etc., is usually provided on one side or both sides with a coating ofglue or any other adhesive to give the loose material such firmness asis required during subsequent handling. The glue is ordinarily appliedby spraying liquid glue onto the respective side of the sheet materialor by covering the side with glue in form of foam, and wadding thustreated is subsequently run over a drum drier.

When wet non-woven fibrous sheets are dried, approximately 100 grams ofwater are evaporated per sq. m. When sheets of greater thickness aredried, a part of the steam developed during drying passes through thesheets to the outside, while a part of the steam will be retained in thesheets. In the case of very thin and permeable sheets, for instance, ofa thickness of 1 to 2 mm. only and a weight of 30 to 50 grams only persq. m., the sheets lack the storing capability for steam. When wetwadding contacts a hot drying drum, water is explosively converted intosteam and tears the wadding.

The primary object of the present invention is to overcome the damagingtearing effects of the explosive conversion of water into steam and toprovide apparatus which will ensure the formation of undamaged finishedwadding and similar materials.

With this object and such other objects as will be apparent from thefollowing description in view, my invention relates to apparatus fordrying materials, such as wadding in sheet form. The apparatus includesrotatable drying drum means and hollow pressure roll means, the latterbeing mounted so as to allow the sheet of material to be dried to be fedbetween the drying drum means and the pressure roll means. The shell orshells of the pressure roll means are apertured. Such apparatus greatlyhelp prevent an explosionlike formation of steam during drying and, thustearing of the wadding.

The invention provides further an association of the referred to dryingdrum means and pressure roll means with an exhausting device. When adrying drum and a pressure roll are used alone, it happens that steamforms deposits on the pressure roll and wadding, which at times makesthe wadding cling to the pressure roll, and this, in turn, may result inbreaks and clevages of the wadding. A device which draws off the steamas it forms prevents water from being deposited on the wadding andpressure roll and this precludes tearing and splitting in an absolutelysafe manner.

According to another aspect of the invention, I provide means to blowsteam as it forms away from the pressure roll and the sheet material.

Generally, the present invention aims at improved apparatus for themanufacture of sheet wadding and similar flat loose materials to makesure that the occurrences during drying will not lead to a damagedfinished product.

The referred to features and their attendant advantages, as well asother features and advantages of this invention, will be fullyappreciated as the same will be apparent from the following detaileddescription when considered in connection with the accompanying drawingsin which:

FIG. 1 illustrates schematically and fragmentarily an apparatusaccording to the invention for drying sheet wadding and the like;

FIG. 2 shows also schematically and fragmentarily a modified apparatus;

FIG. 3 shows a detail of another modification of the apparatus of theinvention; and

FIG. 4 shows a detail of still another modification of the apparatus.

Referring to the drawings now in detail, sheet wadding 1 is fed betweena rotatable drying drum 2 and an apertured pressure roll 3 in thedirection of the arrow shown next to the dash-dot line indicating thewadding. The wadding is pressed onto the drum 2 by the roll 3 which iscarried by two arms 4. These arms are mounted to swing about an axis 5.Below the roll 3, there is a steam-exhausting device which includes anexhausting head 7 and a number of conduits 6.

The head 7 is mounted so that steam will be drawn off both from thepressure roll and the wadding a short distance following the passage ofthe wadding between the drum 2 and the roll 3. The head 7 is preferablyof angular shape.

The swinging mounting of the pressure roll 3 makes it possible to adjustthe space between the drying drum and the pressure roll to the thicknessof the wadding and to other requirement as they exist in each specificcase. The pressure roll may be positively driven or may idle.

In the case of the construction of FIG. 2, a sheet 8, for instance, ofcarded cotton, on the left side of which (looking at the drawing) aliquid glue has been sprayed, is pressed onto a drying drum 2 by meansof a pressure roll 3. The shell of the roll 3 is shown to be apertured.The apertures may be of any suitable shape. Interiorly of the pressureroll, there is a solid conduit 11 for air. In the showing selected forillustration, the longitudinal axis of the conduit 11 makes an anglewith the line connecting the axes of the drum 2 and roll 3. The upperend of the conduit registers with the opening of an air supply pipe 12provided outside the roll 3. Air passing through the pipe 12 strikesfirst upon, and thereby dries, the shell of the roll 3. The air passeson through the conduit and leaves the pressure roll below the nearestdistance between the drying drum and the pressure roll. As the airleaves the conduit 11, it presses the sheet 8 onto the drying drum.

It is within the scope of this invention to narrow the exit end of aconduit which is otherwise similar to the one designated 11 to ensure anozzlelike effect and thus an increased air emergence speed. Also, it ispossible to arrange for the conduit 11 and the pipe 12 to be movablerelative to the roll 3 and the drum 2 within certain limits, so that theplace of the air discharge may be varied.

In the pressure roll 3 shown in FIG. 3, an air pipe 14 does not endshort of the shell of the pressure roll, as does the pipe 12 in FIG. 2,but enters the pressure roll. Air admitted in this way passes throughthe conduit 15 and escapes at both ends thereof. Air escaping at 16presses the material to be dried onto a drying drum, and at the oppositeend of the conduit 15 air escapes over a curved structure 17, therebydrying the pressure roll both from the inside and the outside.

In FIG. 4, a pressure roll 3 is provided with two air chambers 13 and19. From a common air supply line 22, air flows through a branch pipe 20to the chamber 18, and through a branch pipe 21 to the chamber 19. Airflowing through the chamber 18 serves to dry the pressure roll, whereasair flowing through the chamber 19 dries the material to be dried.

It is believed that the construction and operation of the apparatus ofthe invention, and the many advantages thereof, will be understood fromthe foregoing detailed description of a few forms for practicing theinvention.

The invention uses a pressure roll which is apertured and furthers theescape of steam formed during drying. The invention, according to oneaspect thereof, provides the use of an exhausting installation to drythe pressure roll and to make sure that it stays dry. The exhaustingdevice draws off steam continuously and prevents the sheet material fromsticking to the drying dnlm and pressure roll. Similar beneficialresults are ensured by blowing air according to the invention onto andinto the pressure roll. Air flows over the outer and inner faces of thepressure roll or any desired portions thereof and, in a directed jet,toward the sheet material near after the passage of the sheet materialthrough the narrowest distance between the drying drum and the pressureroll. Preferably, air under pressure is used. The air may be heated forgood results.

When using a pressure roll that is adjustably mounted to be movablerelative to the drum, the pressure to be exerted by the pressure rollupon the drying drum may be varied. This makes it possible, with the useof low pressure, to obtain sheet material having a glue surface of usualappearance and properties.

When using increased pressure, sheet material having a perfectly smoothsurface is obtained. Such smooth surface is equal to calenderedsurfaces, so that calendering whenever calenders were used so far may beomitted.

It will be apparent that while I have shown and described my inventionin a few preferred forms, many changes and modifications may be madeWithout departing from the spirit of the invention defined in theappended claims.

I claim:

1. Apparatus for drying materials in sheet form, including a rotatabledrying drum, a rotatable apertured pressure roll, said drum and pressureroll being in peripheral pressure relation with one another, allowingthe sheet of material to be dried to be fed between the drying drum andthe pressure roll, and air supply line on the outside of the pressureroll, leading toward and terminating near the shell of the pressureroll, a conduit for air within the pressure roll, the conduit having oneend register with said terminating end of the supply line, and its otherend directed toward the sheet material at a point near after the passagethereof between the drying drum and the pressure roll.

2. In the apparatus according to claim 1, the air supply line and theair conduit being movably mounted.

3. In the apparatus according to claim 1, said other end of the airconduit being formed in a nozzlelike fashion.

4. Apparatus for drying materials in sheet form, including a rotatabledrying drum, a rotatable apertured pressure roll, said drum and pressureroll being in peripheral pressure relation with one another, allowingthe sheet of material to be dried to be fed between the drying drum andthe pressure roll, a conduit for air within the pressure roll, an airsupply line entering the pressure roll from the outside and leading intothe air conduit, a curved structure on the outer face of the pressureroll, the air conduit having one end register with said curvedstructure, and its other end directed toward the sheet material at apoint near after the passage thereof between the drying drum and thepressure roll.

5. Apparatus for drying materials in sheet form, including a rotatabledrying drum, a rotatable apertured pressure roll, said drum and pressureroll being in peripheral pressure relation with one another, allowingthe sheet of material to be dried to be fed between the drying drum andthe pressure roll, an air chamber provided on the outer face of thepressure roll, an air chamber provided inside the pressure roll on theinner face thereof, two air supply lines, each leading to one of saidchambers.

References Qiterl in the file of this patent UNITED STATES PATENTS1,693,818 Lorenz Jan. 15, 1929 1,755,066 Krull Apr. 15, 1930 2,061,976Merckens Nov. 24, 1936 2,209,760 Berry July 30, 1940 2,784,652Hornbostel Mar. 12, 1957 2,919,495 Underhay Jan. 5, 1690 2,952,033Goodwin Sept. 13, 1960 FOREIGN PATENTS 56,513 Sweden Oct. 26, 1920

1. APPARATUS FOR DRYING MATERIALS IN SHEET FORM, INCLUDING A ROTATABLEDRYING DRUM, A ROTATABLE APERTURES PRESSURE ROLL, SAID DRUM AND PRESSUREROLL BEING IN PERIPHERAL PRESSURE RELATION WITH ONE ANOTHER, ALLOWINGTHE SHEET OF MATERIAL TO BE DRIED TO BE FED BETWEEN THE DRYING DRUM ANDTHE PRESSURE ROLL, AND AIR SUPPLY LINE ON THE OUTSIDE OF THE PRESSUREROLL, LEADING TOWARD AND TERMINATING NEAR THE SHELL OF THE PRESSUREROLL, A CONDUIT FOR AIR WITHIN THE PRESSURE ROLL, THE CONDUIT HAVING ONEEND REGISTER WITH SAID TERMINATING END OF THE SUPPLY LINE, AND ITS OTHEREND DIRECTED TOWARD THE SHEET MATERIAL AT A POINT NEAR AFTER THE PASSAGETHEREOF BETWEEN THE DRYING DRUM AND THE PRESSURE ROLL.